Mixer



l. W; LITCHFIELD MIXER Filed Nov. 3. 1950 5 Sheets-Sheet l g- 1932- l. W..LlTCHFlELD 8 MIXER Filed Nov. 5, 1930 5 Sheets-Sheet 2 Aug. 23, 1932.

|. w. LlTCHFlELD 1,873,438

MIXER Filed Nov. 5, 1930 5 Sheets-shew. 3

Aug. 23, 1932. w. LITCHFIELD MIXER Filed NOV. 5. 1930 5 Sheets-Sheet 4 was Patented Aug. 23, 1932 ISAAC w. LITCHFIELD, or: BosroiwMAssAoHUsErrs, nssIGNoR T0 Burris INDUSTRIES.

INCORPORATED, OF; BOSTQN, MASSAGHUSETTS,

A CORPORATION or DELAWARE Application filed iaamar 3, 1930. Serial to. 4 3,040.

This invention relates toan improved form of material mixer and particularly fto"a;mi r er adapted to cause the thorough inter-mim gling of commi-nt' ted substances when suspended in liquid; for example, apparatus of this character ,is particularly useful when employed for mixing hydraulic or Portland cement. I

This invention particularlyprovides apparatus which may be readily handled by a single operator and which does not require power operation; accordingly apparatus oi? this character is particularly useful forwork:

men employedin small'building operatives;

for farmers; owners of small estatesand the like. 7 p V In accordance with this invention the'rnaa teri'al to be mixed is disposed in acontainer or bag of flexible material and the bag is kneaded to cause breakin u an lurn s or the solid or powdered ingredients thatother wise mightoccur and to cause thorough mixing of the-same. Furthermore theapparatus is preferabl so arranged thatflthe relfative movement of the material in the bag may "occur without necessitatinga material change in' the center of gravity ofthe mixture or necessitating any substantial liftingof the material. Thus the bag required to mixa given batchof material-ma be relatively light and the apparatus adapted to be operated by hand. H f 1 Furthermore apparatus of this character may conveniently be made-in such a way that it may be disassembled when not inuse and stored in a relatively small place. The provision of a container or bag. offfieiiible ma terial also provides conveniently and readily controllable means for removing material from the mixer for use. For this, purpose a portion of the bag may be lowered by means of suitable apparatus to cause some of the material in suspension to flow out th-rough a suitable outlet. Preferably th'eba'g croontainer which is employed is formedofrubber or material having substantiallythej characteristics of a rubber composition; materials of this sort being particularly advantageous since the'hardened or certain oeme titi us material may be readily removed or stripped from the rubber surface. Accordingly the container maybe readily cleaned after use, and particular care to avoid caking or clog ging of the apparatus is not,necessary.

In the accompany drawings:-

Fig. Us a 'vertical'elevation of the assembled mixer;

- Fig. 2 a plan view of thesame; Fig. 3 is a horizontal section along the line 3 3 of Fig. dot-dash lines; 4

- F'g. 't's'a section similar to Fig. '3 show ing the "kneading rolls in engagement with thebag;

Fig. 5 is a vertical section through one 'of the vertical frame members'showing the op eration of the kneading mechanism; 1

6 is a section along the line 6-6 of 1g. a Fig. 7 is a-fragmentary section of the inner ring on the bag showing the adjustable fea- Fig. "8 is an elevation view of one of the arms which actuates the bag. l

The frame 1 comprises three verti-cal legs -5 2 3 and 4 which're'st upon a base member 5, the base member being preferably provided with. a group of roll members to permit ready movement from place to place. The frame is connected at the top by a horizontal mem- 39 her 6 'andadjacent the bottom by a horizontal memberi, the member 6 2;) having the shapeofa spider comprising a central p'or tion and legs extending outwardly to connect with each vertical member of the frame. The frameis preferably secured together as by boltsor the like in order 'to p'er'mit ready disassembly of the respective parts for transportation.

The bag or basket 8, which contains the material tobe m xed, is of any suitable flexible material, preferably of rubber or the like, in order to provide a material to which hardened cement will not readilyadher'e and from thesurfacepf which cement is easily removed and is provided with a thickened rubber ring '8 at its periphery. The basket is clamped along its periphery beneath the rubber ring andheld in-shape-by metal rin-gst and 10 (Fig. 5t between which the periphery o fthe No 1, the bag being shown in 60 V riphery between the two rings.

bag through which an eye-bolt 12 extends and to which 1t is firmly secured by nut's13 and 14on'either side of the member 11. The center and edge of the bag are held at sub:

stanti ally the same elevation, in normal posi tion as shown in Fig.5, and the bag sags between the center and edge to give a cross sectional appearance of a catenary, themae terial holding portion beinggin the form of a r1ng.'.

In orderto hold said basket in normal position and to permit the basket to be raised and lowered as desired, I provide a. pair of spaced grooved pulleys 15 (Fig. 2) in the sameplane in each of thelegs ofthe spider member 6 of the frame, each of the pulleyshavinga peripheral' cable receiving. groove. One of the pulleys has the rope or cable receiving groove on theside adjacent the center of the member 61located substantially ov'ertheeye of the bolt 12, the groove in the other pulley on theside remotefrom the center of the member 6 being substantially directly over the edge of the basket. A cable or rope 17, having an open hook 18 on each end, which is readily attachable to or detachable from the'bag, extendsover these pulleys, one of the hooks detachably engaging the eye of the bolt 12 at the center of the bag, the other hook engaging a clamp member 19 which is attached to the bag periphery. The cable extends fromthe center of the bag over the pulley adjacent the center of the spider member, outwardly over the other pulley and downwardly to the clamp on the edge of the bag.

In order to impart a rolling motion tothe material in the bag, the center and edge are alternately raised and lowered, the center of the bag bein raised when the edge is lowered, as a result 0 the supporting construction just described. The raising and lowering motion is imparted by a system of crank members. A crank member 20 is pivoted to one of the legs of the frame and isconnected to an arm 21 ported by an extension 23 of the spider mem her 6. The arm 21 is firmly secured on a shaft 24 which extends parallel to oneof the spider legs and along an extension 25 of the member'6 and in spaced relation thereto to the opposite side of the frame, the shaft being'mounted in bearings 26 which are carried by supports 27 attached to the member 6 and projecting upwardly therefrom. Secured to this shaft 24 area plurality of arms 28 to each ofwhich a rope or cord 29 is attached at the end remote from the shaft. A

frame member 7 beneaththe bag,

as shown,

' frame as, shown in by a link member 22, the arm being sup pulley member 30is supported on an exten-. 7

located over the 'center of the bag and con ne'ctedto the eye of the bolt12. I a

A plurality of levers or arms (Figs. 3 and 4) for kneading the bag are mounted on the the point of support for these levers being substantially beneathxthe sagging portion of the bag,- that is,'the portion into whichthe material to be mixed isinserted. I I- prefer to use six. levers three of them indicated at 33 being in. line with thevertical .legsof the frame members, the others 34, being spaced midway therebetween,.the levers 33 which are in line with the legs having the upper end of the leyer projecting into the central portion, on the underside of the bag as in Fig. 5, the remaining levers 34' projecting upwardly tothe outside .of the-bag, as shown in'Fig. 3. Each of the levers 33 is held in the position whieh does not distort the bag,'as in Fig.3, by a spring 35 connected ,to the lower end of eachof the levers at one end, the other end of each ofthe springs beingattached to the I Fig.5. The lower ends of the levers 34 are similarly provided with a set of springs 36 which are connected together at theirother end, at'the center of the machine as shown in Fig. .3 and cause the bag engaging portions of, thelevers to remain in normal non-distortion position. The end of the levers where they engage the bag are provided withellipsoidal rolls 37, the end of the lever being forked as at 38 tore ceive the roll and provide a bearing support on either side thereof. 7

- These'levers or kneading arms are actuated by a rope or cable system. Each of the vertical frame'members is slotted as at 39, and carries near the base of the slot a pulley 40,- pivoted between the two portions of the frame on either side of'the slot. Each of the lever arms 33 is provided with a projection 41 toward the center of the machine which pivotally mounts a pair of grooved pulleys 42 in thehorizontal plane of the top periphery of the pulleys 4O in the slots and the levers 34 each have a similar projection 42 carrying .a' single pulley 43in substantially the same plane as theother pulleys, this projection 42extending away from the centerof the machine. A slide 44 movable vertically in the slot in the frame carries the ends of the cables 45 which operate the kneading arms. Considering one of the cables one end is attached to the slide 44 in one leg 4. From there the cable is directed downwardly around the pulley 40, over to one of the pul leys 42 on the lever 33. It is then drawn outwardly to pass over the pulley 43 of lever 34: back toward the'center and around. either pulley 42* on the succeeding lever, over the pulley 4:0 in the adjacent leg 3 of the frame member and up to the slide mounted in the i erted 011 each of the blocks is accordingly substantially equal, the cable being held tight by the movement of the levers. apparent that the movement of the levers is made substantially equal by the particular arrangement of the cables around the levers resulting in substantially uniform movement'for each of the levers. Thus the bag receives a. uniform kneading action for each vertical movement of the slide members. As a result of this construction the material in the bag is subjected to a more positive kneading since the levers will move substantially a predetermined distance whatever the amount of material adjacent thereto in the bag. .Furthermore the slack on the cables, when the bag is released for dumping is compensated by the spring action of the cables, since, as the cables are loosened the levers swing apart a greater extent to hold the I cables tight.

The slide 44 (Fig. 6) comprises a block 46' of a size to fit within the slot. At either end of the block a plate member 47 is secured toretain the block in place. A hook member48 i s secured between the plate and block on the inner side, the member forming a loop 49 (Fig. at the top engaging with a projection 50 on the clamp member 19, and a plurality of loops at the bottom engaging with the cords or cables 45 which operate the kneading arms. A stop member 51 on the frame prevents excessive downward movement of the slide when the hooks 18 are disengaged from the clamps 19 when the basket is to be dumped. j

The clamp 19 is constructed to retain the rings 9 and 10 in place and also as a support for the bag to which the hooks 18 may be attached. A flat member 52 has a projection 53 thereon which en a es beneath therin 9 to prevent slipping and has at the opposite end of the portion 52 a hole into which the hook 18 is inserted. A second projection55 forms a part of ahinge by whichthe member 52 is connected to the inner clamping member 56. This inner clamping member has a projection 57 which engages beneath the ring 10. A clamping screw projects through a slot in the member 52 into a threaded hold in the member 56. By tightening up on this It will be the bag.

screwthe clamping members 46 and 4:9 are drawn toward each other firmly clamping the rings 9 and 10 together. The pin 50 which projects outwardly from the clamp engages with the loop 49 onthe slide 45; In order to permit adjustment of :the rings to acconrimodate the bagmaterial between them, the slotted construction of ring 10 is employed. Their ring is. formed to have overlapping ends 60 and '61, the end 60 having a headed pin 62 secured thereto which engages a longitudinal slot 63 in the end 61 to maintain a substantial ring shapeibut to permit-enlargement or decrease in size for varying bag thicknesses. To facilitate dumping of the bag a detachable trough member 65 is mounted on the side of the basket and is connected to and supported by the rings. Material maybe poured, when desired, out through the trough the outlet being located beneath the rings, and the trough being hooked over the edge of the basket during dumping. a

. The operation of the machine is as follows:

the material to be mixedis placed in the con tainer as shown most clearly in Fig. 5. The operator thenturns the: crank member which causes the arms 28 to rotate through a wide angle, the central arm being raised as the outer armsare being lowered. As the central arm-is raised the center ofthe basket raises therewith and theperiphery ofthe basket is lowered by reason of the cable suspension'between center and edges. Thus the material in the basket is given a rotary movement without, however, raising or lowering its position relative to the frame, thus -leav-' ing the center ofgravity of the device substantially constant. r

As the periphery is raised the kneading levers or arms are drawn into distorting position as in Fig. i and as the periphery is lowered the :arms return to normalor non-distorting position. Clearly, by reason of the reciprocating block in the leg members being secured to the clamps 19, the block must be raised as the clamps are raised, thus drawing upwardly on the cables 45. As the cables are drawn upwardly they draw inwardly on the arms 34 and outwardly on arms 33, drawing the bag into the configuration of Fig. 4 causing a squeezing and kneading action on the material within the bag. The rolls 37 prevent damage-to the bag due to their smooth surface and permit the raising and lowering action of the bag to takeplaceduring the kneading action by their rolling contact with As the periphery of the bag lowers the arms retract out of kneading position into the position of Fig. 3. Thus all the mixing is accomplished from one crank member.-

When the material is suitably mixed the hooks carried by the cables which are conporting cables 17.

that the-material may be removed as desired by pressing downwardly on the outer portion of the bag, which lowers the edge and raises the center of the bag so that the 'material therein Will flow out through the trough member.

her carrying When the dumping is completed the hooks again engage the clamps and a new mixture may be placed in the bag.

In order to transport the machine from place to place the structure is disassembled,

the bag being readily removed by detaching the hooks from The top connecting member is removed from the remaining structure, the connecting memthe kneading arms is removed and the entire machine will occupy a small space, the vertical members being readily removable from the base.

Accordingly I have provided a flexible container which is supported by a frame having a plurality of legs, each of said legs carrying a kneading device which is operated by a device which raises theedge'of the basket and lowers the center and alternately lowers the edges and raises the center. As-the edge 7 is raised and lowered the kneaders are drawn into and retracted from distorting position. I have also provided a readily separable structure which may be packed into a small space for removal from place to place.

It should be understood that the present disclosure is for the purpose ofillustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. A device of the character described comprising a flexible container supported in the center and at edges, and means to raise and lower said center while lowering and raising said edges to impart rotating motion to material in the container, and means to lower a portion of the edge beyond normal operating position to permit dumpingof the container. v

2. A device of the class described comprising a flexible container, means alternately to raise certain portions of said container while lowering other portions, and to lower said certain portions while raising said other portions, means alternately to press against and retract from said container to knead materia1 within the container, and means connecting said kneading means to said raising and lowering means.

3. A device of the character described comprising a flexible container adapted to contain material to be mixed, said container havthe clamps and the eye-bolt.

ng its central portion and its edges supportedto form a bag of substantially ring shape to hold the material, a plurality. of arms'projecting within the ring, and means to actuate said arms into a position tov distort said ring.

4. A device of the character described comprising a flexible containeradapted to containmaterial to be mixed, said container having its central portion and its edges supported to form a bag of. substantially ring shape to hold the material, a plurality of arms within the ring and correspondingarms without the ring, means to actuate said arms into a position to distort said ring and mean-s to. retract said arms from distorting position.

5. A device of the character described comprising a flexible container adapted to contain material to be miXed, said container having its central portion and its edges supported to form a bag of substantially ring shape to hold the material, a plurality of arms Within the ring and corresponding arms without the ring, means connecting said arms to actuate them simultaneously into position to distort said. ring to thereby knead the material within the bag.

6. A device for mixing materials comprising a container for said material, means alternately to raise and lower certain portions of said container simultaneously with a corresponding lowering and raising of certain other portions and means to operate upon said container to change its shape to thereby knead the material.

7. A device for mixing materials comprising a container for said material, means alternately to raise and lower certain portions of said container simultaneously with a corresponding lowering and raising ofcertain other portions and means to operate upon said container to change its shape to thereby knead the material, said last means-and said first means being actuated by a single means. 8. A device for mixing materials comprising a pliable container, means connecting certain portions to other portions whereby said other portions are lowered when said certain portions are raised, without substan-- tially changing the center of gravity of said container, and kneading means alternately to distort and release said container to knead material therein, means for raising and lower ing said certain portions and also for actuating said kneading means. I I

9. An apparatus of the class described com prising a flexible container supported at its edges and central portion, and interconnected means for simultaneously lowering the center While raising the edges of said container and raising said edges while lowering said center, said means including a plurality of rocker arms, cables connecting said arms with the edges and central portion of said container,

and actuating means associated with said rocker arms.

10. Apparatus of the character described comprising a frame, a flexible container slidably supported at its edges and central portion, mechanism for mixing and kneading material within said container, said mechanism including a plurality of kneading arms pivotally secured to said frame and engage able with exterior portions of said container, said kneading arms being adapted alternately to distort and release said container, a plurality of rocker arms, cables connecting said rocker arms with the kneading arms and edges and central portion of the container, and a crank associated with said rocker arms for simultaneously actuating said kneading arms and raising the central portion while lowering the edges of said container and raising the edges while lowering the central portion.

11. A mixing apparatus comprising a flexible container having its central portion and edges supported to form an annular-shaped bag portion adapted to hold material to be mixed, and means for kneading material within said bag, said means comprising a plurality of movable arms engaging the outer surface of said container both within and without said annular-shaped portion.

12. A mixing apparatus comprising a flexible container having its central portion and edges supported to form an annular-shaped bag portion adapted to hold material to be mixed, a plurality of symmetrically disposed movable arms engaging the outer surface of said container both within and without said annular-shaped portion, and mechanism for actuating said arms alternately to distort and release said bag. 7

13. A mixing apparatus comprising a frame, a flexible container having its central portion and edges supported to form an annular-shaped bag portion adapted to hold material to be mixed, a plurality of symmetrically disposed arms pivotally secured to said frame, said arms engaging the outer surface of said container both within and without said annular-shaped portion, mechanism for actuating said arms to knead material within said bag, said mechanism comprising a plurality of levers, cables connecting said levers and arms, and a crank associated with said levers and adapted to cause said arms alternately to distort and release said bag.

Signed by me at Boston, Massachusetts this thirty-first day of October, 1930.

ISAAC W. LITCHFIELD. 

